How to use jQuery with rails webpacker 3

Question

I generate a new rails app : rails new titi --webpack=vue

and would like to use jQuery (or other libs like popper, vue-resource...).

I tried to yarn add jquerywhich was fine, but I don't have access to jQuery in my JavaScript code.

In previous Webpacker gem, there was much more conf and I had to write this in shared.js :

module.exports = {
    ...
    plugins: [
      ...
      new webpack.ProvidePlugin({
          $: 'jquery',
          jQuery: 'jquery',
    ]
    ...
    resolve: {
      extensions: settings.extensions,
      modules: [
       resolve(settings.source_path),
        'node_modules'
      ],
      alias: {
        jquery: "jquery/src/jquery",
        vue: "vue/dist/vue.js",
        vue_resource: "vue-resource/dist/vue-resource",
    }
}

What is the cleanest way to include libraries in current Webpacker version ? Something in config/webpacker.yml?

Answer 1

Updated for Webpacker 3.5.0 and [email protected]

Popper.js and [email protected] aren't required to install JQuery. However, Bootstrap 4 requires both JQuery and Popper.js, and I assume that is the point of showing them in the original example. Also, I omitted Vue from my example as there is ample documentation on how to add the Vue connections.

To get everything to work, I installed webpack-merge, popper.js, jquery, jquery-ujs, and [email protected] via Yarn.

Once installed, I was able to update ./config/webpack/environment.js with the following code:

/*
  ./config/webpack/environment.js
  Info for this file can be found
  github.com/rails/webpacker/blob/master/docs/webpack.md
*/

const { environment } = require('@rails/webpacker')
const merge = require('webpack-merge')
const webpack = require('webpack')

// Add an additional plugin of your choosing : ProvidePlugin
environment.plugins.prepend('Provide', new webpack.ProvidePlugin({
    $: 'jquery',
    JQuery: 'jquery',
    jquery: 'jquery',
    'window.Tether': "tether",
    Popper: ['popper.js', 'default'], // for Bootstrap 4
  })
)

const envConfig = module.exports = environment
const aliasConfig = module.exports = {
  resolve: {
    alias: {
      jquery: 'jquery/src/jquery'
    }
  }
}

module.exports = merge(envConfig.toWebpackConfig(), aliasConfig)

Now that envConfig.toWebpackConfig() is used in the last statement in environment.js, I needed to change development.js, production.js, test.js to the following:

const environment = require('./environment')

module.exports = environment

Then in ./app/javascript/application.js I added the following:

// ./app/javascript/application.js

/* eslint no-console:0 */
// This file is automatically compiled by Webpack, along with any other files
// present in this directory. You're encouraged to place your actual application logic in
// a relevant structure within app/javascript and only use these pack files to reference
// that code so it'll be compiled.
//
// To reference this file, add <%= javascript_pack_tag 'application' %> to the appropriate
// layout file, like app/views/layouts/application.html.erb

console.log('Hello World from Webpacker')

// JS libraries
import "jquery"
import "jquery-ujs"
import "bootstrap"

To make sure JQuery wasn't being loaded via the asset pipeline, I removed the Rails assets connection in ./app/assets/javascripts/application.js:

// require rails-ujs
// require_tree .

I then added these two lines to the header section in ./app/views/layouts/application.html.haml to display the Webpack content:

= stylesheet_pack_tag 'application'
= javascript_pack_tag 'application' 

After making a static_pages controller and static_pages#index view, after starting the Rails server (rails s), I was able to go to my browser's JS console and run console.log(jQuery().jquery); to see if JQuery was loading. Everything loaded as expected.

Documentation can be found here: https://github.com/rails/webpacker/blob/master/docs/webpack.md